Vaporizer for vacuum fumigation



May l, 192&

S. l. GLEASON VAPORIZER FOR VACUUM FUIIGATION Filed May 9, 1925 3 Sheets-Sheet l May 1, 1928.

S. l. GLEASON VAPORIZER FOR VACUUM FUIIGATION Filed May 9. 1925 3 Sheets-Sheet 3 AfroRAI/r .Patented May l, 1928.

UNITED STATES i 1,668,068 PATENT OFFICE.

SHELLEY I. GLEASON, E LOS ANGELES, CALIFORNIA, ABSIGNOB TO UNION AND PIPE COMPANY, OIE LOS ANGELES, CALIFORNIA, A CORPORATION 0l' CALIFORNIA.

VAPORIZEB FOB VACUUM FUMIGATION.

Application filed Hay 9, 1925.

This invention relates to fumigating apparatus, and it particularly concerns a device for producing a toxicant which is of particular value in vacuum fumigation.

At the present time it is customary to practice vacuum fumigation by use of an apparatus which has an hermetically closed vessel in which articles to be fumigated are placed, this vessel being capable of resisting 1U atmospheric pressure. After the articles have been placed in the vessel, a vacuum is created therein, thusremoving all of the air therefrom. The vapors of a toxicant are then introduced into the exhausted vessel.

l5 These vapors are left to act, for a certain length of time, upon the bodies or articles to be fumigated. After this period of time has elapsed, depending upon the character of the articles being fumigated, the vapors are exhausted from the vessel and air is allowed to enter. After the vessel is thoroughly `washed with air, which washing comprises the drawing of clean air therethrough, the articles are removed therefrom completely funiigated.

Hydrocyanic acid is used extensivel as a toxicant in vacuum fumigation. is toxicant, however, is effective only on certain things. Hydrocyanic acid is of such a character that it is absorbed by the things having a high moisture content. For this reason it is not entirely effective for fumigation purposes for all products due to the rapid vitiation of this gas by absorptions into the water content. Further', hydrocyanic acid is very dangerous to handle. lt is a deadly poison and people have been known to be killed thereby.

In an application entitled Process of mixing fumigatinggases and composition of same, filed May 9, 1925, Serial No. 29,110, I presentedto the Patent Office a new fumigating agent which is adapted especially for vacuum fumigation use. This toxicant of my invention is composed of a lethal agent and a vehicle for carrying same. It is nonpoisonous to human beings, which is a very important advantage over hydrocyanic acid. This renders the handling thereof easy. Further, it is efficacious where hydrocyanic acid fails, that is to say, it is not absorbed by dampness and is therefore useful for fumigating many articles which cannot be fumigated by hydrocyanic acid. I desire to Serial `le. 29,109.

use carbon-bisulphide as a. lethal agent.l Carbon-bisulphide has no aflinity for moisture and its effects are therefore not attenuated by the presence of water. Neither does it leave a disagreeable after-odor, this making it satisfactory for use on foodstuffs.

.It is an object of my invention to provide an apparatus for producing a. toxicant such as produced in the above referred to application. My apparatus comprises broadly a gasifying chamber, bafiles in said gasifymg chamber and means for heating sald gasifying chamber. A lethal agent is lntroduced into the chamber, where it is heated and where va orization begins. A vehicle gas is passe through the lethal agent in the gasifying chamber, carr in away therewith lethal agent vapors w ic combine with the vehicle to form a toxicant.

It is another object of this invention to provide an apparatus of this character, in which the bafiies may be easily cleaned. The apparatus is so constructed that the baiiles may be readily removed and openings provided therein readily cleaned. It sometimes occurs that the substances used to produce a toxicant of my invention have impurities which clog the orifices in the baiiles. For example, I prefer to use carbon-bisulphide as a lethal agent. Impurities are sometimes carried in this composition in the form of sulphur. This sulphur tends to collect and clog the openings of the bale plates. This clogging, if occurring to any extent, entirely restrains the passage of fluid through the apparatus and causes considerable damage by the building up of a high pressure in the gasifying chamber.

It is also an object of my invention to provide in an apparatus of the character mentioned a means for accurately measuring a dose of lethal agent. This means is provided in the form of a cylinder, having a graduated tube associated therewith. The lethal agent is supplied to this cylinder, in which the proper dose is measured.

It is a still further object of my invention to provide an apparatus which is operated by the suction of the fumigating vessel of a fumigating apparatus, and therefore no special pumping means is necessary. I accomplish this by connecting the pipes from the fumigating vessel to the gasiying chamber and to the graduated cylinder.

When it is desired to measure adose of lethal agent, a valve is opened vwhich subjects the cylinder to a vacuum, this drawing the lethal agent thereinto. When the .roperamount has been drawn into the cy inc er, the valve just mentioned is closed. When it is desired to draw a lethal a ent and vehicle into the gasifying chain r, a valve in the pi e connected thereto is opened, which subjects the gasifying chamber to a vacuum. Thisdraws a lethal agent and the' -vehicle thereinto. As the lethal agent,

which is preferably in the form of a liquid, is vaporized, these lethal vapors are carried from the gasifying chamber by the vehicle, the combined gases forming a toxicant which isv drawn into the fumigatmg vessel.

Other objects and the especial advantages of my invention will be` emphasized in the following description.

Referring to the three sheets of drawings in which I illustrate a preferred form of Iiiy invention,

Fig. 1 is a diagrammatic view showinor a complete fumigating apparatus employing a'vaporizer ap aratus o my invention.

Fig. 2 is an e evational view of a vaporizer of my invention.

IFig. 3 is an elevational view of my vaporizer taken substantially as indicated by the arrow 3 of Fig. 2.

Fig. 4 is a plan view of my vaporizer.

' Fig. 5 is a vertical sectional view taken through the va orizer cleait'lly showing the gasifying cham er and ba e construction and other features thereof.

Fig. 6 is a cross section taken substantially as indicated by the line 6-6 of Fig. 5, this view clearly showing the web construction for supporting the gasifying tank of my invention.

Fig. 7 is a cross section taken substantially on the line 7--7 of Fig. 5, this view clearly showing thebatlle arrangement of my invention.

Fig. 8 is a cross section taken on the line- 8-8 of Fig. 5.

Fi 9 is an enlarged fragmentary sectiona view showing an injector arrangement em lo ed in my invention.

itil reference to Fig. 1 of the drawings, I show a fumgating vessel or treating tank 11, in which articles to be fumigated are placed. This vessel 11 has a cover 12 which 1s removable so as to provide admittance for articles to be fumigated and which is capable of securement so as to tightly seal the vessel 11. A vacuum pump 13 connects with the vessel 11 by means of a pipe 14 having a valve 10. When the vacuum pump 13 is operated, the interior of the vessel 11 is placed under a vacuum. A 'gauge is secured in communicationwith the interior of the vessel 11, by which the condition of vacuum therein is indicated. An air inlet 1,eea,oss

pipe 16 is connected with the vessel 11, this pipe 16 having a valve 17 therein. The air pipe 16 is provided for the purpose of admitting air to the vessel 11 during the washing thereof, which will be explained later. A pipe 20 extends from the vessel 11 and connects to a vaporizer 25, which embodies the features of my invention.

Vith reference to the other figures of the drawings, the vaporizer of my invention is provided in the form of an outer shell 26 having a tight bottom 27 and a removable top 28. The shell 26 is supported by a suitable standard 28*.V A heating liquid 29 is carried in the shell 26, this liquid being supplied 'thereto by means of an inlet pipe 36 ia'ving suitable valves 31 therein. The pipe 30 connects, as clearly shown in Fig. 2, with the upright portion of the standard 28a. The level of the liquid 29 which is preferably water, is registered on a gauge glass 33 carried on the exterior of the shell 26, as clearly shown in Fig. 5. Electric heating elements 34 extend into the shell 26 for the purpose of heating -the water 29.

An inner shell 35 providing a gasifying chamber 36 is supported inside the outer shell 26 by means of a supporting web 37 as clearly shown in Fics. 5 and 6. The web 37 has a central cylindrical opening 38 therethrough, through which the shell 35 is extended. The lower edge of a iange 39 which is secured at the u per end of the shell 26 engages an upper ace of the web 37, thus supporting the inner shell 35 in place. The fiange 39 carries a plurality of pivoted bolts 41 having wing nuts 42. These bolts and wing nuts are adapted to tightly clamp a cover 43 upon the open end of the shell 35.

Connected to the cover 43 and extending upwardly therefrom is a pipe 45. This pipe 45 extends through an opening 46 in the top 28 of the outer shell 26 and connects to a pipe 47 having a valve 50 by means of a union 48. The pi e 47 is connected with the pipe 20, which eads to the vessel 11 by means of a union 49. The pi e`47 also connects with a safety pipe 51 having a valve 52 therein, by means of a union 54.

A batlie arrangement 56, as clearly shown in Fig. 5, is carried in the gasifying chamber 36. This arrangement is provided in the form of a central supporting bar 57 having a handle 58 formed at the upper end thereof. Secured to the support 57 is a plurality of collars 59 which supports a series of batile plates 61. These baile plates 61 comprise flat plates which extend in a radial plane and com letely close the gasifying chamber 36. owever, these baiiie plates 61 have openings 62 therethrough.4 The openings in the lowest baille plate 61 are preferably about 1/4th inch in diameter, and the openings in the uppermost baiile plate 61 are preferably about 7 /64ths inch in di- 1,ees,oes

ameter. Near the center of the gasifying chamber 36 I place sleeve bales 65 and 66. The sleeve battle 65 has a closed bottom 67 which is supported by one of the collars 59, and the sleeve baille .66 has a flange by which it is secured to the upper edge of the sleeve battle 65. as indicated at 71. In the bottom 67 of the baille 65 holes 73 are provided. It will be noted from Fig. 7 that these holes 73 are arranged about the exterior of the bottom plate ofthe sleeve bafile 66.

Secured at the lower end of the support 57 is a dcflector 75 which rests on a bottom 76 of the inner shell 35. Openings 78 are provided in the deflector 75.

The baille arrangement 56 is removable. This feature however will be explained later.

A measuring cylinder 85 is secured to the side of the outer shell 26 by suitable brackets 81. The measuring cylinder 85, as clearly shown in Figs. 2 and 3. has a graduated tube 87 extend-ing along the side thereof, this tube being connected to the lower end of the cylinder 85 by a fitting 88 having a valve 89 and being connected to the upper end of the cylinder 85 by a Iitting 91 having a valve 92. This graduate-'tube 87 is provided with graduations 93.

From the lower end of the cylinder 85 there extends a pipe 94 having a cross fitting 95 connected thereto. vExtending from one leg ot the cross 95 is a pipe 96 having a valve 97, this pipe 96 extending upwardly, as shown, and connects by means of a union 99 to a pipe-100. The pipe 100 is connected to a pipe 101 by means of a union 102. The pipe 101 extends to the interior of the shell 26, passing through an opening 103 in the top 28. This pipe 101 extends to a point near the bottom of the shell 26 and connects to an injector 105. As shown in Fig. 9, the pipe 101 connects with a nozzle 106 of the injector 105, this nozzle being situated inside the body 107 of the injector 105. Also connected with the cross 95 is a lethal agent inlet pipe 108 having a valve 109. A 'drain pipe 111 is connected with the remaining leg of the cross 95, this pipe 111 having a valve 112. The upper end of the cylinder 85l has a pipe 119 connected thereto. which extends to the safety pipe 51, this pipe 119 having a shut-off valve 120. Also connected to the top of the cylinder 85 is a short pipe 121 opening to the atmosphere and having a valve 122.

A vehicle gas is introduced into the vaporizer 25 by means of a pipe 125 having a valve 126. This pipe 125 connects by means of a union 127 to a short pipe 128. The pipe 128 connects to a pipe 129 by means of a union 130. The pipe 129, as clearly shown in Figs. 5, 8 and 9, extends through an opening 132 in the top 28 and extends to a point near the bottom of the shell 26. As shown metically seal the interior of the vessel 11.

The valve 50 in the pipe 47 which connects with the pipe 20 and the valve 17 in the air inlet pipe 16 are closed, and the valve 10 in the pipe 14. is opened. The vacuum pump 13 is then operated to evacuate the vessel 11. In this manner all of the air is withdrawn from the vessel 11 and a vacuum of substantially 28 inches is placed o'n the vessel. The valve 10 is then closed and the pump 13 shut down. The electric heating elements 33 are energized to heat the body of water 29 in the shell 26. This water is heated to a temperature of about 140 F., which is indicated on u. thermometer 140. This temperature is suitable when using carbon-bisulphide as a lethal agent, this temperature being suflicient to vaporize this substance. The next step is to measure the proper dose of lethal agent Which is accomplished as follows. The va1ves'122, 109, 97 and 112 are closed. The valves 50 and 120 are then opened, which subjects the vaporizing chamber 36 and the interior of the measuring cylinder 85 to a vacuum. The valve 109 in the lethal agent inlet pipe 108 is opened. Carbon-bisulphide is then drawn into the measuring cylinder 85 by the vacuum placed thereupon. As the carbon-bisulphide liquid flows mto the measuring cylinder, the level thereof is indicated on the graduated tube 89. lVhen the proper amount is drawn into the cylinder, which is readily noted on the graduations 93 on the graduated tube 87, the valve 109 is closed and the valve 120 is also closed. f

A vehicle gas is then allowed to enter the gasifying chamber 36. This is accomplished by opening the valve 126 in the pipe line 125, this valve 126 being opened only a slight degree, however. I prefer to use carbondioxide as a vehicle gas.

The lethal agent is then introduced into the gasit'ying chamber 36. This is accompished by opening the valve 122 which subject-s the interior of the measuring cylinder 85 to atmospheric pressure. The valve 97 in the pipe line 96 is then opened and the lethal agent is forced through this pipe by the pressure of the atmosphere on the top of the body of liquid in the cylinder 85. The lethal agent passes through the pipes 96, 100 and 101 to the injector 105. The liquid passes from the nozzle 106 of the injector 105 with considerable force, impinging against the deflector and being broken u and diffused thereby. When all of the liquld has passed from the cylinder 85, which is disvehicle gas to pass into the gasifying chamber 36. The lethal agent is heated while in the'gasifying chamber 36 andvaporization thereof commences. The `vehicle "as in pass ing through this body picksup tli ese vapors and lcarries them upwardly therewith,

through the gasifying chamber 36, through the pipes 45, 47 and 20, into the .vessel 11.

prevent any liquid particles of vthe lethal agent from being carried vwith the vehicle gas. This is very effectively accomplished by passing the vehicle gas through the open-` iing-62 in the baille 61. This tends to rob the I may drain therefrom through the openings 73. The openings 73, as previously describe-d, are arranged to the. exterior of the cylindrical baiile 66. Thay are thus arranged so that in case any iquid should be vforced upwardly .through these cpenin s, it

would not pass through the cylin cal .ailie e* g 66. This might occur due to excessive resi're in the lower part of the gasifying cham- This operation is carried on until the vessel 11 reaches atmospheric pressure which is indicated on thel gauge 15. The lethal agent is vaporized entirely before the chamber 11 reaches atmospheric ressure, but the vehicle is passed through t e vaporizer until this atmospheric pressure in the vessel 11 has been reached. At this time the valve 50 -is again closed. The temperature in the cham.- ber-ll is ordinarily suilicient to prevent an appreciable condensation of the lethal agent. The toxicant which is composed of the vehicle gas and lethal agent is left in the vessel 11 for a length of time, depending upon .the character of the articles being fumlgated. When this riod has elapsed, the valve 10 in the pipeine 14 is opened and the vacuum pump 13 put into operation. This removes the toxicant from the vessel 11. The valve 17 in the air inlet pipe 16 is then opened and air is drawn into the vessel 11 by the vacuum pump 13, thoroughly washing samesofas to assure the removing of all -of the toxicant vapor. The` cover 12 is then removed froml place and the articles thoroughly fumigated areremoved.

As previousl mentioned, it is. impossible to obtain an a solute vacuum of 30 inches. With standard equipment a vacuum of about Solved sul hur. .on the ba es 61 and in time will clog the bon-bisulphide is measured in the measuring cylinder 85 and is then drawn into the gasifying chamber 36.' The temperature and -5\ ressure of the gas in the fumigating chame baille arrangement 56 is provided to r is'substantia ly atmospheric. The-'length of time that things are subjectcdj to the toxicant varies according tothe characters-of these'articles. For example,

potatoes are subjected to the action of the toxlcant for one hour and fifteen minutes,

almonds for one hour and thirty minutes,

and raisins for oneJ hour. l

`When the toxicant or fumgating'agent is withdrawn by the vacuum pumpf-13 from the vesselll, 1/15th of the capacity of the vessel 11, or 60 cubic'feet, is left therein. For l this reason the vessel 11'- is air-washed so that this remaining toxicant maybe re'- moved. The air washing ofthe vessel 11 is generally carried on for a period of about five minutes. 4

' Carbon-bisulphide possesses qualities which are -very favorable for vacuum fumigation. It smothers animal life, is a fat solvent and is somewhat poisonous. Carbon-bisulphide vhas one disadvantage, and that is that it is inflammable. In experimenting I used air as a vehicle. Much care had to be exerted to prevent an explosion due to the combining of oxygen in this air with the carbon-bisulphide. For this reason I use carbon-dioxide which is an inert gas and will not cause. an explosion because there will be no chemical action thereofwith the. carbon-bisulphide.

As previously mentioned, I use only 200 'cubic feet of carbon-bisulphide,`whereas I use740 cubic feet of carbon-dioxide. It is advantageous to use this excess of carbonj dioxide because it counteracts the presence of the 60 cubic feet of air left in the vessel jsul hide vand result in an explosion.

' t is'not always possible to obtain an absolutely pure carbon-bisulphide, impurities being carried therein in the form of dis- This sul hurl will collect openings 62 therein. lIt is necessary at intervals to remove the baille arrangement 56 to clean the openings 62 in the baffles 61. This is accomplished by detaching the unions 48, 49 and 54 which permits a-re moval of the pipe47.' It isalso necessary guapos to detach the unions 127 and 130 to remove the portion of pipe 128 and t0 detach the unions 99 and 102 to remove the pipe 100. The top 28 of the shell 26 is then detached and removed from place. This gives access to the interior of the shell 26 so that the wing nuts l42 may beiloosenedand the cover 43 removed from the inner shell 35. The baffle arrangement 56 is then removed by lifting this arrangement upwardly out of the gasifying chamber 36. The handle 58 prov1des a convenient grip for the bafile arrangement.

Excessive pressures which might be created in the lower portion of the asifying chamber 36 by an expansion of tv e carbon-bisulphide, which might occur in the event of a clogging of the baflles, may. be readily counteracted by o ening the valve 52 in the safety pipe 51, tiis allowing air to rush thereinto and to return the entire system to atmospheric pressure.

From the foregoing.description-it is obvious that the apparatus of my invention operates to econonucally produce a fumigating gas or toxicant. The apparatus is operatedautomatically by the vacuum in the vessel 11. A desiredl dose of carbon-bisulphide or other lethal agent may be quickly and accurately measured by the measuring arrangement of my invention. The baffles may be readily removed and easily cleaned. The measuring cylinder may be drained of any water or foreign substance by opening the valve 112.

I claim as my invention:

1. In an apparatus of the character described, the combination of: walls forming a gasifying chamber; means for introducing a lethal fluid into said gasifying chamber, said lethal fluid forming a body in the lower part of said gasifying chamber; means for passing a. vehicle gas through said body of lethal fluid in said gasifying chamber, said vehicle gas carrying gasified particles of said lethal fluid therewith; and means for conducting said lethal fluid and said vehicle gas from said gasifying chamber.

2. In an apparatus of the character described, the combination of: walls forming a gasifying chamber; means for introducing a lethal fluid into said gasifying chamber, said lethal fluid forming a body in the lower part of said gasifying chamber; means for passing a vehicle gas through said body of ethal fluid in said gasif ing chamber, said vehicle gas carrying gasi ed particles of said lethal fluid therewith; means in said gasify ing chamber for preventing fluid articles of said lethal fluid from being carried with said vehicle gas; and means for conducting said lethal fluid and said vehicle gas from said gasifying chamber.

3. In an apparatus of the character described, the combination of: walls forming a gasifying chamber; means for introducing a lethal fluid into said gasifying chamber, said lethal fluid .forming a body in the lower part of said gasifying chamber; means for passing a veh1cle gas through said body of lethal fluid in said gasifying chamber, said veh1cle gas carrying gasified particles of said lethal fluid therewith; baffles situated in said `gasit'ying chamber for preventing fluid p artlcles of said lethal fluid from being carried with said vehicle gas; and means for 'conducting said lethal fluid and said vehicle gas from said gasifying chamber.

In an apparatus of the character de scrlbed, the combination of: walls forming a `gasifying chamber; means for heating sa1d gasif ing chamber; means for introducing a. ethal fluid into the lower end of said .gasifying chamber, said lethal fluid forming a body in the lower part of said asifying chamber; means connected to the ower part of said gasifyinv chamber for passing a. vehicle gas through said body of lethal fluid in said gasifying chamber, said veh1cle gas carrying gasified particles of said lethal fluid therewith; baflles situated in said gasifying chamber for preventing fluid particles of said lethal fluid from being carried with said vehicle as; and means for conducting said lethal uid and said vehicle gas from said gasifying chamber.

5. In an apparatus of the character described, the combination of: walls forming a gasifying chamber; means for introducing a lethal fluid into said gasifying part' of said gasifying chamber; means for passmg a vehicle gas through said body of let-hal fluid in` said gasif ing chamber, said vehicle gas carrying gasi ed particles of said lethal fluid therewith; removable baffles situated in said gasifying chamber for preventing fluid particles of said lethal fluid from being carried with said vehicle gas, said removable baffles consisting of a support and baffle plates carried by said support short distances from each other, and means for conducting said lethal fluid and said vehicle gas from said gasifying chamber.

6. In an apparatus of the character described, the combination of: walls forming a gasifying chamber; means for measuri a dose of lethal fluid; means for introduclng said lethal fluid into said gasiging chamber, said lethal fluid forming a ody in the lower part of said gasifying chamber; means foi-passing a. vehicle gas through said body of lethal fluid in said gasifying chamber, said vehicle gas carrying gasified particles of said lethal fluid therewith; and means for conducting said lethal fluid and said vehicle gasfrom. said gasifying chamber.

7. In an apparatus of the character described, the combination of: walls formin a gasifying chamber, said gasifying chamer chambergi. lsaid lethal fluid forming a body 1n the lower"V`V las lower part of said gasifyin being under a vacuum; means for introducing a lethal fluid into said gasifying chamf berl means for introducing a vehicle gas into said gasifying chamber; and means or conducting said ethal fluid and said vehicle gas from said gasifying chamber.

8. In an apparatus of the character described, the combination of: walls forming a asifying chamber, said gasifying cham er eing under a vacuum; means for introducing a lethal iiuid into said gasiying chamber, said lethal fluid forming a body in the 0' chamber; means for passing a vehicle gas through said body of lethal fluid in said gasifying chamber, said vehicle gas carrying gasified particles of said lethal fiuid therewith; and means for conducting said lethal fluid and said vehicle gas from said gasifying chamber.

9. In an apparatus o the class described, the combination of: an inner shell forming a asifyingchamber; an outer shell forming a eating chamber around said gasifymg chamber, said heating chamber being arranged to contain a heatin fluid; means for heating said heating ui ;4 a conduit connected to said gasi in chamber, said conduit being connecte w1th a means for placing said gasifying chamber under a vacuum; means through which a lethal liquid is drawn into said ifying chamber, said lethal liquid formlng a body therein; and means through which a vehicle gas is drawn into said gasifying chamber, said vehicle -gas being drawn through said body and through V y said conduit.

10. In an apparatus of the class described, the combination of: an inner shell forming a asiying chamber; an outer shell forming a eating chamber around said gasifymg chamber, said heatin chamber being ari,

ranged to contain a eating fluid; means for heating said heating Huid; -a. conduit connected to said gasi mg chamber, said conduit being connecte placing said gasifying chamber. under 'a with a means for.

vacuum; means through which a lethal chamber, said heating' chamber being .arf

ranged to contain a heatin fluid; means forv heating said heating lling; `a-conduit connected to said gasif ing duit bei connect I withv a means for placing sai gasifying chamber under a vacuum; means throu h which a lethal` liquid is drawn into sai gasifnchamber, sa1d lethal liquid forming a therein; means through which a vehic e gas is drawn into said vehicle gas being rawn through `said body and through said conduit, sai vehicle gas carrying particlesof gased lethal liquid f .fil y prevent therewith; and bailles arranged to liquid particl from being carried' y vehicle gas.

In testimony whereof I have ies, California, this' I set my hand at Los Ange 4th day of Ma ,1925. l y HELLEY I. GLEASON.

(gasifying chamber, saidchamber, said con- 

